Before and After: Boston Marathon Photos

This combination of April 15, 2013 and April 10, 2014 photos, shows people running away from a bomb blast along Boylston Street near the finish line of the Boston Marathon, and a patron entering a taxi on the same street nearly a year later in Boston.

Bob Leonard/Elise Amendola/AP Photo

This combination of April 15, 2013 and April 10, 2014 photos, shows people running away from a bomb blast along Boylston Street near the finish line of the Boston Marathon, and a patron entering a taxi on the same street nearly a year later in Boston.

Bob Leonard/Elise Amendola/AP Photo

This combination of April 15, 2013 and April 14, 2014 photos shows medical workers aiding injured people on Boylston Street near the finish line of the 2013 Boston Marathon following two bomb explosions, and nearly a year later traffic flowing on the same street as preparations are being made for the 2014 Boston Marathon in Boston.

Charles Krupa/AP Photo

This combination of April 15, 2013 and April 14, 2014 photos shows medical workers aiding injured people along Boylston Street after the first of two bombs exploded near the finish line of the 2013 Boston Marathon, then pedestrians walking along the same sidewalk almost a year later in Boston.

Charles Krupa/AP Photo

This combination of April 16, 2013 and April 9, 2014 photos show a runner passing a police officer dressed in tactical gear blocking a road leading to the Boston Marathon route the morning after two bomb blasts killed three people and injured 260 more, and traffic on that street almost a year later during a normal weekday in Boston.

Charles Krupa/AP Photo

This combination of April 15, 2013 and April 10, 2014 photos show a view of Boylston Street in front of the Forum restaurant, where investigators comb for evidence at the site where the second of two bombs exploded near the finish line of the 2013 Boston Marathon, and pedestrians walking past the same spot almost a year later in Boston.

Elise Amendola/AP Photo

This combination of April 15, 2013 and April 10, 2014 photos show a view of Boylston Street in front of the Marathon Sports store, left, the site where the first of two bombs exploded near the finish line of the 2013 Boston Marathon, and pedestrians walking along the same sidewalk almost a year later in Boston.

Elise Amendola/AP Photo

This combination of April 15, 2013 and April 2, 2014 photos show a police officer clearing Boylston Street following a bomb blast near the finish line of the 2013 Boston Marathon, and pedestrians crossing at the same corner nearly a year later in Boston.

Charles Krupa/AP Photo

This combination of April 19, 2013 and April 9, 2014 photos show law enforcement authorities searching for Boston Marathon bombing suspect Dzhokhar Tsarnaev in Watertown, Mass., and a view of the same street as children return home from school almost a year later.

Charles Krupa/AP Photo

This combination of April 19, 2013 and April 9, 2014 photos show police going door-to-door as they searched for Boston Marathon bombing suspect Dzhokhar Tsarnaev in Watertown, Mass., and a child walking past the same home after school almost a year later.

Charles Krupa/AP Photo

This combination of May 7, 2013 and April 10, 2014 photos shows Kevin Brown placing a Teddy bear at a makeshift memorial near the Boston Marathon finish line in Copley Square, and people walking through the same square at lunchtime nearly a year later in Boston